VW 01M gearbox: faults and reliability

• 01M (4 speeds, 1995-2005)

  1995–2005 · 01M

  With caution

  Its documented faults (wiring and speed sensors, valve body wear, speedometer gear) can be checked on a test drive and with a diagnostic reader; a workshop that knows the 01M is advisable, because Wikipedia warns that many general workshops do not master it.^[1][2]

Buy: No known serious faults, or they have already been corrected, in this version. With caution: Worth buying if something specific is verified: history, a replaced part or a completed campaign. Avoid: High risk of a serious fault that is hard to check for or prevent.

1. 1High severityFrequency: OccasionalTransmissionValve body wear and internal pressure leaks (slipping and jerking)With mileage, the aluminium valve body housings wear and the piston diaphragms rupture: the 01M loses internal pressure and shows long or harsh shifts, vibration or slipping of the converter lock-up and, in some cases, stalling.
2. 2Medium severityFrequency: OccasionalElectronicsWiring and speed sensor (G38 and G68) faults and emergency mode in third gearOver the years the resistance of the wiring and terminals between the valve body and the 01M's control unit increases, and the unit stops reading the speed sensors and goes into emergency mode: the gearbox is locked in third. Ross-Tech cites VW bulletins with additional wiring harnesses.
3. 3Medium severityFrequency: OccasionalTransmissionBroken plastic speedometer gearThe plastic gear that drives the speed sensor (G22) on the 01M's differential can break internally and leave the speedometer dead and sometimes the cruise control too. Repairing it means removing the gearbox and opening the differential.

Severity colours: low, medium, high, critical. How we rate them

Manufacturer

Volkswagen Group (diseño de origen Renault)

Family

Familia de automáticas de 4 velocidades de origen Renault (AR4, AD4): la 096 (1992-1994) precedió a la 01M (1995-2005, motor transversal); la 097 de Audi (motor longitudinal) pasó a llamarse 01N, y la 098/01P va en la Transporter T4. La 09A (Jatco) y la 09G (Aisin, ver su ficha) fueron sus sucesoras.

Type

Automatic with torque converter with lock-up and epicyclic gear sets, 4 speeds, transverse mounting

Production

1995–2005

Makes

Volkswagen, Audi, Seat and Škoda

Technical data^[1]

1. 1995–2005

   01M (4 speeds, 1995-2005)

   The only version covered by this entry: the 01M, an electro-hydraulic 4-speed automatic with transverse engine, with different ratios depending on the engine and the car (identified by a three-character code on the starter motor flange; a wrong set of ratios makes the control unit go into emergency mode).^[1]